Dynamics of active tracer in dilute and arrested states in dense 2D lattice; Dr. Rakesh,Chatterjee (School of Mechanical Engineering and Sackler Center for,Computational Molecular and Materials Science, Tel Aviv, Israel)

ABSTRACT: We analyze the dynamics of an active tracer particle
embedded in a thermal lattice gas. All particles are subject to
exclusion up to third nearest neighbours on a square lattice, which
leads to slow dynamics at high densities. With no rotational diffusion
of the tracer, we derive an analytical expression for the resulting
drift velocity of the tracer in terms of non-equilibrium density
correlations involving the tracer particle and its neighbours. For the
case where the tracer undergoes rotational diffusion, we relate its
diffusion coefficient to the thermal diffusion coefficient and drift
velocity. We also study dynamics where the rotation of the tracer is
limited by the presence of neighbouring particles.

Next we explore phase separation and kinetic arrest when all particles
are active and have infinite persistence time of their active
orientation. The passive limit of the model quenches into the
two-phase coexistence region represent an aging passive glass. Adding
small persistent active bias to the particle dynamics creates states
that resemble the passive glass at lower densities. For large active
bias, the dense, immobile clusters proliferate until a spanning
network bridges the system leading to percolation of an arrested
phase.